Waste filter for waste incineration

First, the characteristics of the smoke from the incinerator of domestic waste To purify the smoke, we must first understand the characteristics of the incineration of domestic waste. The fumes generated from the incineration of domestic waste have the following characteristics: 1. The moisture content of the smoke is large. This is because the original water content in domestic garbage is large, and some hydrocarbons also generate water vapor in combustion. The general moisture content is 23 to 30%. 
2. Due to the complex composition of waste, the toxic and harmful components in the fumes produced after combustion are also complex, including trace amounts of metals such as mercury, cadmium, lead, molybdenum, chromium, nickel, and copper. In addition, the particle size of the resulting particulate matter is also relatively small and the viscosity is high. 
3. The smoke composition is also complicated. Unlike coal-fired boilers, it contains not only O2, SOx, CO2, NOx, but also acid gases such as HCl, HF, steam, and total hydrocarbons (THC). This must be carefully studied and considered when selecting the filter media. 
4. Carcinogens such as dioxins and furans may also be produced during combustion and are extremely harmful to humans. In general, activated carbon is sprayed before the bag filter to adsorb it. This should also be noted. 
5. Fine particle size and high viscosity. 
From the above characteristics, it can be seen that the purification and dedusting of the incineration flue gas of domestic garbage is both of great difficulty and very important.
Selection of bag-type pulse dust collector 1. Determination of dust removal method of bag filter
The commonly used cleaning methods for bag filter are anti-blowing, vibration and pulse cleaning methods. Anti-blow, vibration cleaning method, low energy consumption, but the general choice of filter speed is also about half lower than the pulse cleaning method, which led to a large area, increasing the initial investment costs.
In terms of dust collection efficiency, the difference between the two is not great. This is because the dust layer on the filter material is not easily "over-removed", and the problem often arises in the garbage incineration is that the dust is not good, that is, the ash on the filter bag does not come down, resulting in resistance. Increasing. 
Baghouse dust collectors on waste incinerators are preferably constructed with a chamber. This facilitates maintenance without affecting the operation of the incinerator. And after the sub-room can be used three-state cleaning method to improve the cleaning effect. 
When using pulse bag filter, we generally use the injection pressure of 4.5 ~ 6.5kg/cm2. 
2. Determination of bag filter
(1) The amount of flue gas to be burned must first be determined correctly. Because the size of the bag filter depends on the filter area, once it is determined, it will not change. If the smoke volume estimate is small, the actual filtration speed will be large, resulting in large equipment resistance and poor cleaning, which will make it difficult to continue the long-term operation. If the estimate is large, the initial investment in equipment is high, but there will be no problem in operation. 
(2) Be careful to choose well-made equipment. Especially the components and components of the pulse jet system, the inspection doors, the ash output, the ash conveying device, the cooperation of filter bags and flower plates, the design and processing quality of the filter bag cage bones (finishing and verticality, etc.) should be good. Otherwise it will affect the long-term good operation of the equipment. 
The material of the filter should consider the following factors: temperature resistance, acid resistance, alkali resistance, oxidation resistance, etc. In addition, due to the high humidity of the waste incineration flue gas, the ability to resist hydrolysis is a factor that must be taken into account when selecting the filter material. Due to the difference in the price of the filter bag material, the final choice is often the result of a one-time investment and operating costs and the results of comprehensive consideration. Different filter materials use temperature, dust removal efficiency, dust removal performance, cost, and corrosion resistance of different chemical components in the flue gas are not the same and need to be considered comprehensively. 
The general choice of filter materials are: glass fiber filter, Teflon, Ryton, P84, Gore-tex and so on. Ryton filter material has good acid resistance, hydrolysis resistance, and abrasion resistance, and the price is not too expensive, as long as the oxygen content of the flue gas is lower than its tolerance level (different temperatures can tolerate different oxygen content ), can get good results. P84 is better at capturing dust than Ryton, but it is less resistant to hydrolysis than Ryton. Goltax has good performance, but the price is higher. Teflon has good acid and alkali resistance, but it is expensive. Fiberglass cloth cannot filter HF-containing gases, but the price is more appropriate. 
(3) Pay attention to the acid dew point of smoke. When the flue gas temperature is lower than the acid dew point, the acid produced by condensation will corrode the equipment and form a soot bond on the filter material. Therefore, some measures must be taken for the dust removal system, such as ash hopper heating, hot air circulation, pipe bypass, equipment insulation, and flue gas heating. 
(4) The selection of filter bag materials for waste incineration pulse dust collectors. According to the nature of the smoke and the composition of the smoke, choose a suitable filter. The choice of filter material is the key. If the filter material is not suitable, the service life will be affected. However, the cost of replacing the filter material is not cheap.